Vertical diffusion processes in the Eastern Mediterranean — Black Sea System

On the Circulation and Thermohaline Properties of the Eastern Mediterranean Sea

“…Areas located between the two stable layers, as well as those located below the LIW to the whole vertical extent of the PG, are affected by SF. The sensitivity of the Ionian 200-1000 m layer to the SF condition was previously highlighted by Zodiatis (1992) and Kioroglou et al (2014), by analysing CTD profiles, and by Meccia et al (2016) using model reanalysis products. In late fall, the MLD starts to increase typically reaching a depth between 150 and 300 m in the period January-March.…”

“…In terms of water column stability, the PG and the CG are strongly characterized by the SF regime alternated to winter mixing events (Figures 5-8). The sensitivity of the Ionia Sea to the SF is attributed to the hot and saline LIW waters filling the basin from 200 to 400 m at various places, overlying the less saline and colder resident waters (Zodiatis, 1992;Onken and Brambilla, 2003;Kioroglou et al, 2014). This condition also occurs in the PG not only in the layer below the LIW, but also in the subsurface layer (50-80 m depth) at the interface between the saltier and warmer LSW and the underlying water (Figure 5).…”

“…This condition also occurs in the PG not only in the layer below the LIW, but also in the subsurface layer (50-80 m depth) at the interface between the saltier and warmer LSW and the underlying water (Figure 5). In the layer below 1000 m, the water column of the Ionian Basin is considered stable with some sporadic shifts toward the SF or DC regimes caused by temporary intrusions of waters with different thermohaline properties (Kioroglou et al, 2014;Meccia et al, 2016). This condition does not occur in the PG, where, the layers located below its vertical extension (red and blue dots in the deep layer of Figure 5B) show instability down to 2000 m (not shown), suggesting the occurrence of deep mixing phenomena in this layer.…”